Fuel cells may be used to provide power for cars and homes, and distributed hydrogen production systems such as hydrogen filling stations may become commonplace. Safe implementation of hydrogen may be desirable for commercial acceptance of fuel cell technology. Hydrogen safety sensors may be important components of such fuel cell systems. Conventional hydrogen sensors may lack desirable: sensitivity; low cross-sensitivity to other contaminants such as carbon monoxide, hydrocarbons, and volatile organic compounds; response and recovery times, long-term stability, and the like. For chemical resistor type hydrogen sensors, desirable performance characteristics may include, for example: broad H2 detection range, e.g., 1000 ppm (parts per million) to 1%; H2 sensitivity, e.g., >50% resistance change at 1% H2 in air; wide ambient temperature range, e.g., −40 to 200° C.; response time t90 to 90% resistance change responsive to change in H2 concentration, e.g., <30 seconds; broad humidity range, e.g., 0 to 100% RH; low cross-sensitivity, e.g., none to CO, CH4, NH3, humidity, VOCs, or other gases; no recalibration, e.g., stable baseline resistance and sensitivity; low power, e.g., less than 1 watt; low, e.g., 0-5 volt signals compatible with low-cost electronics; and the like.
The present application appreciates that providing capable hydrogen sensors may be a challenging endeavor.